diff --git a/element_array_ephys/probe.py b/element_array_ephys/probe.py
index 124646a9..d433ed53 100644
--- a/element_array_ephys/probe.py
+++ b/element_array_ephys/probe.py
@@ -137,6 +137,7 @@ def create_neuropixels_probe_types():
         "neuropixels 2.0 - SS",
         "neuropixels 2.0 - MS",
         "2013",
+        "NP2004",
     ):
         if not (ProbeType & {"probe_type": probe_type}):
             create_neuropixels_probe(probe_type)
diff --git a/element_array_ephys/readers/spikeglx.py b/element_array_ephys/readers/spikeglx.py
index 0eb48999..b8e6d2a0 100644
--- a/element_array_ephys/readers/spikeglx.py
+++ b/element_array_ephys/readers/spikeglx.py
@@ -96,15 +96,15 @@ def get_channel_bit_volts(self, band="ap"):
                 dataVolts = dataInt * Vmax / Imax / gain
         """
         vmax = float(self.apmeta.meta["imAiRangeMax"])
+        imax = self.apmeta.meta.get("imMaxInt")
+        imax = float(imax) if imax else IMAX[self.apmeta.probe_model]
 
         if band == "ap":
-            imax = IMAX[self.apmeta.probe_model]
             imroTbl_data = self.apmeta.imroTbl["data"]
             imroTbl_idx = 3
             chn_ind = self.apmeta.get_recording_channels_indices(exclude_sync=True)
 
         elif band == "lf":
-            imax = IMAX[self.lfmeta.probe_model]
             imroTbl_data = self.lfmeta.imroTbl["data"]
             imroTbl_idx = 4
             chn_ind = self.lfmeta.get_recording_channels_indices(exclude_sync=True)
@@ -266,7 +266,7 @@ def __init__(self, meta_filepath):
         self.probe_PN = self.meta.get("imDatPrb_pn", "3A")
 
         # Infer npx probe model (e.g. 1.0 (3A, 3B) or 2.0)
-        probe_model = self.meta.get("imDatPrb_type", 1)
+        probe_model = self.meta.get("imDatPrb_type", 0)
         if probe_model < 1:
             if "typeEnabled" in self.meta and self.probe_PN == "3A":
                 self.probe_model = "neuropixels 1.0 - 3A"
@@ -283,7 +283,7 @@ def __init__(self, meta_filepath):
         elif probe_model == 24:
             self.probe_model = "neuropixels 2.0 - MS"
         else:
-            self.probe_model = str(probe_model)
+            self.probe_model = self.probe_PN
 
         # Get recording time
         self.recording_time = datetime.strptime(